Agonist-induced PKC phosphorylation regulates GluK2 SUMOylation and kainate receptor endocytosis
Autor: | Daniel L. Rocca, Philip Rubin, Sophie E.L. Chamberlain, Sriharsha Kantamneni, Kevin A. Wilkinson, Filip A. Konopacki, Jeremy M. Henley, Nadia Jaafari, Jack R. Mellor |
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Rok vydání: | 2011 |
Předmět: |
Agonist
Kainic acid medicine.drug_class media_common.quotation_subject Blotting Western SUMO-1 Protein SUMO protein Kainate receptor Biology Endocytosis 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Receptors Kainic Acid Chlorocebus aethiops Serine medicine Animals Humans Phosphorylation Rats Wistar Internalization Cells Cultured Protein Kinase C Protein kinase C 030304 developmental biology media_common Neurons 0303 health sciences Alanine Kainic Acid Microscopy Confocal Multidisciplinary Sumoylation Biological Sciences Rats Cell biology Luminescent Proteins HEK293 Cells Amino Acid Substitution chemistry COS Cells Mutation 030217 neurology & neurosurgery |
Zdroj: | Proceedings of the National Academy of Sciences |
ISSN: | 1091-6490 0027-8424 |
Popis: | The surface expression and regulated endocytosis of kainate (KA) receptors (KARs) plays a critical role in neuronal function. PKC can modulate KAR trafficking, but the sites of action and molecular consequences have not been fully characterized. Small ubiquitin-like modifier (SUMO) modification of the KAR subunit GluK2 mediates agonist-evoked internalization, but how KAR activation leads to GluK2 SUMOylation is unclear. Here we show that KA stimulation causes rapid phosphorylation of GluK2 by PKC, and that PKC activation increases GluK2 SUMOylation both in vitro and in neurons. The intracellular C-terminal domain of GluK2 contains two predicted PKC phosphorylation sites, S846 and S868, both of which are phosphorylated in response to KA. Phosphomimetic mutagenesis of S868 increased GluK2 SUMOylation, and mutation of S868 to a nonphosphorylatable alanine prevented KA-induced SUMOylation and endocytosis in neurons. Infusion of SUMO-1 dramatically reduced KAR-mediated currents in HEK293 cells expressing WT GluK2 or nonphosphorylatable S846A mutant, but had no effect on currents mediated by the S868A mutant. These data demonstrate that agonist activation of GluK2 promotes PKC-dependent phosphorylation of S846 and S868, but that only S868 phosphorylation is required to enhance GluK2 SUMOylation and promote endocytosis. Thus, direct phosphorylation by PKC and GluK2 SUMOylation are intimately linked in regulating the surface expression and function of GluK2-containing KARs. |
Databáze: | OpenAIRE |
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